• Ryan Mathews is 26 years old, playing in his fourth NFL season. Ladarius Green, 23, is an NFL sophomore. Their speed creates problems for defenses but their versatility does not. Can they grow into more-trusted playmakers? The Chargers stand a better chance of scratching out a playoff berth if they do. The second half of San Diego's season, which starts against the Broncos on Sunday, seems a fine time to find out.

• Mathews is having his healthiest season, having played all eight games. He has lost one fumble, the red-zone miscue against Philadelphia in Week 2. Did it spook the coaches? They'd seen a similar fumble in his final carry of the preseason, at Arizona, also near the goal-line.

• Mathews suffered a concussion, also known as a brain injury, in Week 5. He returned to practice three days later and hammered out 100 yards rushing the next two games, the second coming after left tackle King Dunlap, without prompting, declared that getting Mathews 100 yards each week was a goal of the offensive line's. His rushing touchdown in Week 7, at Jacksonville, much-celebrated by the blockers, was his first since Week 5 of last year.

• Sunday against the Redskins, Danny Woodhead turned in another strong performance while playing over Mathews for most of the second half. Woodhead, a reliable pass protector, is a devastating receiver out of the backfield and has the crazy gene that sends him full speed into defenses populated by men who are giants, relative to him. Lining up at either split end or slot receiver, he beats defensive backs and linebackers.

• With Woodhead earning his pay through most of the second half, Mathews touched the ball just once over the final two quarters. He played only five of the half's 34 snaps, none on third down. He was on the sideline for 24 of the offense's last 25 plays.

• Not slick at squirming for yards, Mathews can launch himself over defenders, a way to win on short-yardage plays. He went Superman into the end zone for the rushing TD last year in New Orleans, and soared over a scrum to convert on fourth-and-1 against Seattle's starting defense in this year's preaseason opener. (Later on the drive versus Seattle, the Chargers' new braintrust elected not to go for it on fourth-and-inches, forgoing a low-risk chance to further launch the short-yardage game.) Two weeks later, Mathews shook off a mid-flight collision in scoring a TD at Arizona.

• Mathews lacks large, powerful hands. He seems looser with the ball when hit from the left side. He is a more upright target than Woodhead and not nearly as fluent of a receiver. But he is a fast 215-pounder who can get yards after the first hit (so can Woodhead). At Fresno State, for what it's worth, he scored a school-record 39 touchdowns. Matthews has one more year on his rookie contract. A new coaching staff has eight more games this year to figure out what to do with him near the end zone. Woodhead's under contract next year, too.